1. Field of the Invention
This invention relates to microfiche techniques, and is more particularly concerned with the provision of digital information on a microfiche card, which information is to be retrieved for data processing purposes and/or which information is to be retrieved for the purpose of accurately positioning the microfiche card for the purpose of optical scanning.
2. Description of the Prior Art
It is well known in the art to place control information on reel or cartridge microfilm to identify frames of the microfilm. This information may be in the form of alphanumeric characters which are visually read on a trial and error basis until the desired frame is properly positioned for reading with a viewer. It is also well known in the art to place control information along the edge of a strip of microfilm to be read by an optical scanner in order to place a desired frame within the viewing field of a viewer.
With respect to microfiche cards, however, a card is placed on an x-y transport, generally manually operated, and the desired frame is obtained, again by a trail and error method through repeated repositionings of the card until the frame appears on the viewer.
Heretofore, microfiche cards have been limited to providing graphic illustrations and/or alphanumeric information, such as generally found in parts ordering and inventory systems.
To generally sum up the state of the art, alphanumeric and digital codes have been provided on reel-type microfilm for visual or electronic observation, while microfiche cards have been provided with visual indicators to identify the position of a frame within a matrix of frames on a card.